1
|
Bailey HM, Cookson MR. How Parkinson's Disease-Linked LRRK2 Mutations Affect Different CNS Cell Types. JOURNAL OF PARKINSON'S DISEASE 2024:JPD230432. [PMID: 38905056 DOI: 10.3233/jpd-230432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/23/2024]
Abstract
LRRK2 is a relatively common genetic risk factor for Parkinson's disease (PD), with six coding variants known to cause familial PD. Non-coding variation at the same locus is also associated with sporadic PD. LRRK2 plays a role in many different intracellular signaling cascades including those involved in endolysosomal function, cytoskeletal dynamics, and Ca2+ homeostasis. PD-causing LRRK2 mutations cause hyperactive LRRK2 kinase activity, resulting in altered cellular signaling. Importantly, LRRK2 is lowly expressed in neurons and prominently expressed in non-neuronal cells in the brain. In this review, we will summarize recent and novel findings on the effects of PD-causing LRRK2 mutations in different nervous system cell types. This review will also provide novel insight into future areas of research at the intersection of LRRK2 cell biology, cell type specificity, and PD.
Collapse
Affiliation(s)
- Hannah M Bailey
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Mark R Cookson
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
2
|
Yao XY, Guan LN, Chen Q, Ren C. LRRK2 G2019S and Parkinson's disease: insight from Neuroinflammation. Postgrad Med J 2023; 100:4-11. [PMID: 37777187 DOI: 10.1093/postmj/qgad080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 08/08/2023] [Accepted: 09/01/2023] [Indexed: 10/02/2023]
Abstract
The multiple hypothesis holds that the pathogenesis of Parkinson's disease (PD) requires many factors such as heredity, environment and ageing. Mutations in Leucine-rich repeat kinase 2 (LRRK2) are recognized the risk factors of PD, and closely related to sporadic and familial PD and can regulate a variety of cellular pathways and processes. An Increasing number of studies has shown that glial hyperactivation-mediated neuroinflammation participates in dopaminergic neuron degeneration and pathogenesis of PD. LRRK2 is essential to the regulaton of chronic inflammation, especially for the central nervous system. The review spotlights on the novel development of LRRK2 on microglia and astrocytes, and explore their potential therapeutic targets, in order to provide a new insights in PD. Key messages: What is already known on this topic The G2019S mutation of LRRK2 is now recognised as a pathogenic mutation in PD. Previous studies have focused on the relationship between neurons and LRRK2 G2019S. What this study adds Neuroinflammation mediated by LRRK2 G2019S of glial cells affects the progress and development of PD and attention must be paid to the role of LRRK2 G2019S in glial cells in PD. How this study might affect research, practice or policy Developing anti-inflammatory drugs from the perspective of LRRK2 G2019S of glial cells is a new direction for the treatment of PD.
Collapse
Affiliation(s)
- Xiao-Yan Yao
- Department of Neurology, Yantai Yuhuangding Hospital, Qingdao University, Yantai, 264000, China
| | - Li-Na Guan
- Department of Neurosurgical Intensive Care Unit, Yantai Yuhuangding Hospital, Qingdao University, Yantai, 264000, China
| | - Qi Chen
- Department of Neurology, Yantai Yuhuangding Hospital, Qingdao University, Yantai, 264000, China
| | - Chao Ren
- Department of Neurology, Yantai Yuhuangding Hospital, Qingdao University, Yantai, 264000, China
- Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, Yantai, 264000, China
| |
Collapse
|
3
|
Feng L, Lo H, Hong Z, Zheng J, Yan Y, Ye Z, Chen X, Pan X. Microglial LRRK2-mediated NFATc1 attenuates α-synuclein immunotoxicity in association with CX3CR1-induced migration and the lysosome-initiated degradation. Glia 2023; 71:2266-2284. [PMID: 37300531 DOI: 10.1002/glia.24422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/22/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Synucleinopathies refer to a range of neurodegenerative diseases caused by abnormal α-synuclein (α-Syn) deposition, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). Their pathogenesis is strongly linked to microglial dysfunction and neuroinflammation, which involves the leucine-rich-repeat kinase 2 (LRRK2)-regulated nuclear factor of activated T-cells (NFAT). Of the NFAT family, NFATc1 has been found to be increasingly translocated into the nucleus in α-syn stimulation. However, the specific role of NFATc1-mediated intracellular signaling in PD remains elusive in regulating microglial functions. In the current study, we crossbred LRRK2 or NFATc1 conditional knockout mice with Lyz2Cre mice to generate mice with microglia-specific deletion of LRRK2 or NFATc1, and by stereotactic injection of fibrillary α-Syn, we generated PD models in these mice. We found that LRRK2 deficiency enhanced microglial phagocytosis in the mice after α-Syn exposure and that genetic inhibition of NFATc1 markedly diminished phagocytosis and α-Syn elimination. We further demonstrated that LRRK2 negatively regulated NFATc1 in α-Syn-treated microglia, in which microglial LRRK2-deficiency facilitated NFATc1 nuclear translocation, CX3CR1 upregulation, and microglia migration. Additionally, NFATc1 translocation upregulated the expression of Rab7 and promoted the formation of late lysosomes, resulting in α-Syn degradation. In contrast, the microglial NFATc1 deficiency impaired CX3CR1 upregulation and the formation of Rab7-mediated late lysosomes. These findings highlight the critical role of NFATc1 in modulating microglial migration and phagocytosis, in which the LRRK2-NFATc1 signaling pathway regulates the expression of microglial CX3CR1 and endocytic degradative Rab7 to attenuate α-synuclein immunotoxicity.
Collapse
Affiliation(s)
- Linjuan Feng
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Hsuan Lo
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zhaoxiang Hong
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Department of Neurology, The University of HongKong Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Jiahao Zheng
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Yuhong Yan
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Zucheng Ye
- Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, China
| | - Xiaochun Chen
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Xiaodong Pan
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
- Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, China
| |
Collapse
|
4
|
Cheataini F, Ballout N, Al Sagheer T. The effect of neuroinflammation on the cerebral metabolism at baseline and after neural stimulation in neurodegenerative diseases. J Neurosci Res 2023. [PMID: 37186320 DOI: 10.1002/jnr.25198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 03/23/2023] [Accepted: 03/29/2023] [Indexed: 05/17/2023]
Abstract
Neuroinflammation is a reaction of nervous tissue to an attack caused by an infection, a toxin, or a neurodegenerative disease. It involves brain metabolism adaptation in order to meet the increased energy needs of glial cell activation, but the nature of these adaptations is still unknown. Increasing interest concerning neuroinflammation leads to the identification of its role in neurodegenerative diseases. Few reports studied the effect of metabolic alteration on neuroinflammation. Metabolic damage initiates a pro-inflammatory response by microglial activation. Moreover, the exact neuroinflammation effect on cerebral cell metabolism remains unknown. In this study, we reviewed systematically the neuroinflammation effect in animal models' brains. All articles showing the relationship of neuroinflammation with brain metabolism, or with neuronal stimulation in neurodegenerative diseases were considered. Moreover, this review examines also the mitochondrial damage effect in neurodegeneration diseases. Then, different biosensors are classified regarding their importance in the determination of metabolite change. Finally, some therapeutic drugs inhibiting neuroinflammation are cited. Neuroinflammation increases lymphocyte infiltration and cytokines' overproduction, altering cellular energy homeostasis. This review demonstrates the importance of neuroinflammation as a mediator of disease progression. Further, the spread of depolarization effects pro-inflammatory genes expression and microglial activation, which contribute to the degeneration of neurons, paving the road to better management and treatment of neurodegenerative diseases.
Collapse
Affiliation(s)
- Fatima Cheataini
- Neuroscience Research Center (NRC), Faculty of Medical Science, Lebanese University, Hadath, Beirut, Lebanon
| | - Nissrine Ballout
- Neuroscience Research Center (NRC), Faculty of Medical Science, Lebanese University, Hadath, Beirut, Lebanon
| | - Tareq Al Sagheer
- Neuroscience Research Center (NRC), Faculty of Medical Science, Lebanese University, Hadath, Beirut, Lebanon
| |
Collapse
|
5
|
Is Glial Dysfunction the Key Pathogenesis of LRRK2-Linked Parkinson's Disease? Biomolecules 2023; 13:biom13010178. [PMID: 36671564 PMCID: PMC9856048 DOI: 10.3390/biom13010178] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Leucine rich-repeat kinase 2 (LRRK2) is the most well-known etiologic gene for familial Parkinson's disease (PD). Its gene product is a large kinase with multiple functional domains that phosphorylates a subset of Rab small GTPases. However, studies of autopsy cases with LRRK2 mutations indicate a varied pathology, and the molecular functions of LRRK2 and its relationship to PD pathogenesis are largely unknown. Recently, non-autonomous neurodegeneration associated with glial cell dysfunction has attracted attention as a possible mechanism of dopaminergic neurodegeneration. Molecular studies of LRRK2 in astrocytes and microglia have also suggested that LRRK2 is involved in the regulation of lysosomal and other organelle dynamics and inflammation. In this review, we describe the proposed functions of LRRK2 in glial cells and discuss its involvement in the pathomechanisms of PD.
Collapse
|
6
|
Mechanisms of Autoimmune Cell in DA Neuron Apoptosis of Parkinson's Disease: Recent Advancement. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7965433. [PMID: 36567855 PMCID: PMC9771667 DOI: 10.1155/2022/7965433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 12/23/2022]
Abstract
Parkinson's disease (PD) is a prevalent neurodegenerative disorder that manifests as motor and nonmotor symptoms due to the selective loss of midbrain DArgic (DA) neurons. More and more studies have shown that pathological reactions initiated by autoimmune cells play an essential role in the progression of PD. Autoimmune cells exist in the brain parenchyma, cerebrospinal fluid, and meninges; they are considered inducers of neuroinflammation and regulate the immune in the human brain in PD. For example, T cells can recognize α-synuclein presented by antigen-presenting cells to promote neuroinflammation. In addition, B cells will accelerate the apoptosis of DA neurons in the case of PD-related gene mutations. Activation of microglia and damage of DA neurons even form the self-degeneration cycle to deteriorate PD. Numerous autoimmune cells have been considered regulators of apoptosis, α-synuclein misfolding and aggregation, mitochondrial dysfunction, autophagy, and neuroinflammation of DA neurons in PD. The evidence is mounting that autoimmune cells promote DA neuron apoptosis. In this review, we discuss the current knowledge regarding the regulation and function of B cell, T cell, and microglia as well as NK cell in PD pathogenesis, focusing on DA neuron apoptosis to understand the disease better and propose potential target identification for the treatment in the early stages of PD. However, there are still some limitations in our work, for example, the specific mechanism of PD progression caused by autoimmune cells in mitochondrial dysfunction, ferroptosis, and autophagy has not been clarified in detail, which needs to be summarized in further work.
Collapse
|
7
|
Choi I, Heaton GR, Lee YK, Yue Z. Regulation of α-synuclein homeostasis and inflammasome activation by microglial autophagy. SCIENCE ADVANCES 2022; 8:eabn1298. [PMID: 36288297 PMCID: PMC9604594 DOI: 10.1126/sciadv.abn1298] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 07/11/2022] [Indexed: 05/07/2023]
Abstract
Autophagy clears protein aggregates, damaged cellular organelles, and pathogens through the lysosome. Although autophagy is highly conserved across all cell types, its activity in each cell is specifically adapted to carry out distinct physiological functions. The role of autophagy in neurons has been well characterized; however, in glial cells, its function remains largely unknown. Microglia are brain-resident macrophages that survey the brain to remove injured neurons, excessive synapses, protein aggregates, and infectious agents. Current studies have demonstrated that dysfunctional microglia contribute to neurodegenerative diseases. In Alzheimer's disease animal models, microglia play a critical role in regulating amyloid plaque formation and neurotoxicity. However, how microglia are involved in Parkinson's disease (PD) remains poorly understood. Propagation of aggregated α-synuclein via cell-to-cell transmission and neuroinflammation have emerged as important mechanisms underlying neuropathologies in PD. Here, we review converging evidence that microglial autophagy maintains α-synuclein homeostasis, regulates neuroinflammation, and confers neuroprotection in PD experimental models.
Collapse
Affiliation(s)
| | - George R. Heaton
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - You-Kyung Lee
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | |
Collapse
|
8
|
Microglia Phenotypes in Aging and Neurodegenerative Diseases. Cells 2022; 11:cells11132091. [PMID: 35805174 PMCID: PMC9266143 DOI: 10.3390/cells11132091] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 02/08/2023] Open
Abstract
Neuroinflammation is a hallmark of many neurodegenerative diseases (NDs) and plays a fundamental role in mediating the onset and progression of disease. Microglia, which function as first-line immune guardians of the central nervous system (CNS), are the central drivers of neuroinflammation. Numerous human postmortem studies and in vivo imaging analyses have shown chronically activated microglia in patients with various acute and chronic neuropathological diseases. While microglial activation is a common feature of many NDs, the exact role of microglia in various pathological states is complex and often contradictory. However, there is a consensus that microglia play a biphasic role in pathological conditions, with detrimental and protective phenotypes, and the overall response of microglia and the activation of different phenotypes depends on the nature and duration of the inflammatory insult, as well as the stage of disease development. This review provides a comprehensive overview of current research on the various microglia phenotypes and inflammatory responses in health, aging, and NDs, with a special emphasis on the heterogeneous phenotypic response of microglia in acute and chronic diseases such as hemorrhagic stroke (HS), Alzheimer’s disease (AD), and Parkinson’s disease (PD). The primary focus is translational research in preclinical animal models and bulk/single-cell transcriptome studies in human postmortem samples. Additionally, this review covers key microglial receptors and signaling pathways that are potential therapeutic targets to regulate microglial inflammatory responses during aging and in NDs. Additionally, age-, sex-, and species-specific microglial differences will be briefly reviewed.
Collapse
|
9
|
Zhang M, Li C, Ren J, Wang H, Yi F, Wu J, Tang Y. The Double-Faceted Role of Leucine-Rich Repeat Kinase 2 in the Immunopathogenesis of Parkinson’s Disease. Front Aging Neurosci 2022; 14:909303. [PMID: 35645775 PMCID: PMC9131027 DOI: 10.3389/fnagi.2022.909303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/20/2022] [Indexed: 12/17/2022] Open
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is one of the most common causative genes in Parkinson’s disease (PD). The complex structure of this multiple domains’ protein determines its versatile functions in multiple physiological processes, including migration, autophagy, phagocytosis, and mitochondrial function, among others. Mounting studies have also demonstrated the role of LRRK2 in mediating neuroinflammation, the prominent hallmark of PD, and intricate functions in immune cells, such as microglia, macrophages, and astrocytes. Of those, microglia were extensively studied in PD, which serves as the resident immune cell of the central nervous system that is rapidly activated upon neuronal injury and pathogenic insult. Moreover, the activation and function of immune cells can be achieved by modulating their intracellular metabolic profiles, in which LRRK2 plays an emerging role. Here, we provide an updated review focusing on the double-faceted role of LRRK2 in regulating various cellular physiology and immune functions especially in microglia. Moreover, we will summarize the latest discovery of the three-dimensional structure of LRRK2, as well as the function and dysfunction of LRRK2 in immune cell-related pathways.
Collapse
Affiliation(s)
- Mengfei Zhang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
- Aging Research Center, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Chaoyi Li
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
- Aging Research Center, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Jie Ren
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
- Aging Research Center, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Huakun Wang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
- Aging Research Center, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Fang Yi
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
- Aging Research Center, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Junjiao Wu
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Department of Rheumatology and Immunology, Xiangya Hospital, Central South University, Changsha, China
- Provincial Clinical Research Center for Rheumatic and Immunologic Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Yu Tang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
- Aging Research Center, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| |
Collapse
|
10
|
Russo I, Bubacco L, Greggio E. LRRK2 as a target for modulating immune system responses. Neurobiol Dis 2022; 169:105724. [DOI: 10.1016/j.nbd.2022.105724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 01/08/2023] Open
|
11
|
Novello S, Mercatelli D, Albanese F, Domenicale C, Brugnoli A, D'Aversa E, Vantaggiato S, Dovero S, Murtaj V, Presotto L, Borgatti M, Shimshek DR, Bezard E, Moresco RM, Belloli S, Morari M. In vivo susceptibility to energy failure parkinsonism and LRRK2 kinase activity. Neurobiol Dis 2021; 162:105579. [PMID: 34871735 DOI: 10.1016/j.nbd.2021.105579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/08/2021] [Accepted: 12/02/2021] [Indexed: 12/31/2022] Open
Abstract
The G2019S mutation of LRRK2 represents a risk factor for idiopathic Parkinson's disease. Here, we investigate whether LRRK2 kinase activity regulates susceptibility to the environmental toxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). G2019S knock-in mice (bearing enhanced kinase activity) showed greater nigro-striatal degeneration compared to LRRK2 knock-out, LRRK2 kinase-dead and wild-type mice following subacute MPTP treatment. LRRK2 kinase inhibitors PF-06447475 and MLi-2, tested under preventive or therapeutic treatments, protected against nigral dopamine cell loss in G2019S knock-in mice. MLi-2 also rescued striatal dopaminergic terminal degeneration in both G2019S knock-in and wild-type mice. Immunoblot analysis of LRRK2 Serine935 phosphorylation levels confirmed target engagement of LRRK2 inhibitors. However, MLi-2 abolished phosphoSerine935 levels in the striatum and midbrain of both wild-type and G2019S knock-in mice whereas PF-06447475 partly reduced phosphoSerine935 levels in the midbrain of both genotypes. In vivo and ex vivo uptake of the 18-kDa translocator protein (TSPO) ligand [18F]-VC701 revealed a similar TSPO binding in MPTP-treated wild-type and G2019S knock-in mice which was consistent with an increased GFAP striatal expression as revealed by Real Time PCR. We conclude that LRRK2 G2019S, likely through enhanced kinase activity, confers greater susceptibility to mitochondrial toxin-induced parkinsonism. LRRK2 kinase inhibitors are neuroprotective in this model.
Collapse
Affiliation(s)
- Salvatore Novello
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy.
| | - Daniela Mercatelli
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy; Technopole of Ferrara, LTTA Laboratory for Advanced Therapies, 44121 Ferrara, Italy.
| | - Federica Albanese
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy.
| | - Chiara Domenicale
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy.
| | - Alberto Brugnoli
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy.
| | - Elisabetta D'Aversa
- Department of Life Science and Biotechnology, University of Ferrara, 44121 Ferrara, Italy.
| | - Silvia Vantaggiato
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy
| | - Sandra Dovero
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.
| | - Valentina Murtaj
- Nuclear Medicine Department, San Raffaele Scientific Institute, Milan, Italy; PhD Program in Neuroscience, School of Medicine and Surgery, University of Milano Bicocca, Monza, Italy; Medicine and Surgery Department, University of Milano Bicocca, Monza, Italy.
| | - Luca Presotto
- Nuclear Medicine Department, San Raffaele Scientific Institute, Milan, Italy.
| | - Monica Borgatti
- Department of Life Science and Biotechnology, University of Ferrara, 44121 Ferrara, Italy.
| | - Derya R Shimshek
- Department of Neuroscience, Novartis Institutes for BioMedical Research, Novartis Pharma AG, 4002 Basel, Switzerland.
| | - Erwan Bezard
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.
| | - Rosa Maria Moresco
- Nuclear Medicine Department, San Raffaele Scientific Institute, Milan, Italy; Medicine and Surgery Department, University of Milano Bicocca, Monza, Italy; Institute of Molecular Bioimaging and Physiology (IBFM), CNR, Segrate, Italy.
| | - Sara Belloli
- Nuclear Medicine Department, San Raffaele Scientific Institute, Milan, Italy; Medicine and Surgery Department, University of Milano Bicocca, Monza, Italy; Institute of Molecular Bioimaging and Physiology (IBFM), CNR, Segrate, Italy.
| | - Michele Morari
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy.
| |
Collapse
|
12
|
Troisi J, Landolfi A, Cavallo P, Marciano F, Barone P, Amboni M. Metabolomics in Parkinson's disease. Adv Clin Chem 2021; 104:107-149. [PMID: 34462054 DOI: 10.1016/bs.acc.2020.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Parkinson's disease (PD) is a multifactorial neurodegenerative disorder in which environmental (lifestyle, dietary, infectious disease) factors as well as genetic make-up play a role. Metabolomics, an evolving research field combining biomarker discovery and pathogenetics, is particularly useful in studying complex pathophysiology in general and Parkinson's disease (PD) specifically. PD, the second most frequent neurodegenerative disorder, is characterized by the loss of dopaminergic neurons in the substantia nigra and the presence of intraneural inclusions of α-synuclein aggregates. Although considered a predominantly movement disorder, PD is also associated with number of non-motor features. Metabolomics has provided useful information regarding this neurodegenerative process with the aim of identifying a disease-specific fingerprint. Unfortunately, many disease variables such as clinical presentation, motor system involvement, disease stage and duration substantially affect biomarker relevance. As such, metabolomics provides a unique approach to studying this multifactorial neurodegenerative disorder.
Collapse
Affiliation(s)
- Jacopo Troisi
- Department of Medicine, Surgery and Dentistry, "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy; Theoreo Srl, Montecorvino Pugliano, SA, Italy; European Biomedical Research Institute of Salerno (EBRIS), Salerno, SA, Italy.
| | - Annamaria Landolfi
- Department of Medicine, Surgery and Dentistry, "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Pierpaolo Cavallo
- Department of Physics, University of Salerno, Fisciano, SA, Italy; Istituto Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Roma, RM, Italy
| | - Francesca Marciano
- European Biomedical Research Institute of Salerno (EBRIS), Salerno, SA, Italy
| | - Paolo Barone
- Department of Medicine, Surgery and Dentistry, "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Marianna Amboni
- Department of Medicine, Surgery and Dentistry, "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| |
Collapse
|
13
|
Yao L, Wu J, Koc S, Lu G. Genetic Imaging of Neuroinflammation in Parkinson's Disease: Recent Advancements. Front Cell Dev Biol 2021; 9:655819. [PMID: 34336822 PMCID: PMC8320775 DOI: 10.3389/fcell.2021.655819] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 06/14/2021] [Indexed: 12/14/2022] Open
Abstract
Parkinson's disease (PD) is one of the most prevalent neurodegenerative aging disorders characterized by motor and non-motor symptoms due to the selective loss of midbrain dopaminergic (DA) neurons. The decreased viability of DA neurons slowly results in the appearance of motor symptoms such as rigidity, bradykinesia, resting tremor, and postural instability. These symptoms largely depend on DA nigrostriatal denervation. Pharmacological and surgical interventions are the main treatment for improving clinical symptoms, but it has not been possible to cure PD. Furthermore, the cause of neurodegeneration remains unclear. One of the possible neurodegeneration mechanisms is a chronic inflammation of the central nervous system, which is mediated by microglial cells. Impaired or dead DA neurons can directly lead to microglia activation, producing a large number of reactive oxygen species and pro-inflammatory cytokines. These cytotoxic factors contribute to the apoptosis and death of DA neurons, and the pathological process of neuroinflammation aggravates the primary morbid process and exacerbates ongoing neurodegeneration. Therefore, anti-inflammatory treatment exerts a robust neuroprotective effect in a mouse model of PD. Since discovering the first mutation in the α-synuclein gene (SNCA), which can cause disease-causing, PD has involved many genes and loci such as LRRK2, Parkin, SNCA, and PINK1. In this article, we summarize the critical descriptions of the genetic factors involved in PD's occurrence and development (such as LRRK2, SNCA, Parkin, PINK1, and inflammasome), and these factors play a crucial role in neuroinflammation. Regulation of these signaling pathways and molecular factors related to these genetic factors can vastly improve the neuroinflammation of PD.
Collapse
Affiliation(s)
- Longping Yao
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jiayu Wu
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Sumeyye Koc
- Department of Neuroscience, Institute of Health Sciences, Ondokuz Mayıs University, Samsun, Turkey
| | - Guohui Lu
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| |
Collapse
|
14
|
Leucine-rich repeat kinase 2-related functions in GLIA: an update of the last years. Biochem Soc Trans 2021; 49:1375-1384. [PMID: 33960369 DOI: 10.1042/bst20201092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/13/2022]
Abstract
Missense mutations in the leucine-rich repeat kinase-2 (LRRK2) gene represent the most common cause of autosomal dominant Parkinson's disease (PD). In the years LRRK2 has been associated with several organelles and related pathways in cell. However, despite the significant amount of research done in the past decade, the contribution of LRRK2 mutations to PD pathogenesis remains unknown. Growing evidence highlights that LRRK2 controls multiple processes in brain immune cells, microglia and astrocytes, and suggests that deregulated LRRK2 activity in these cells, due to gene mutation, might be directly associated with pathological mechanisms underlying PD. In this brief review, we recapitulate and update the last LRRK2 functions dissected in microglia and astrocytes. Moreover, we discuss how dysfunctions of LRRK2-related pathways may impact glia physiology and their cross-talk with neurons, thus leading to neurodegeneration and progression of PD.
Collapse
|
15
|
Pons-Espinal M, Blasco-Agell L, Consiglio A. Dissecting the non-neuronal cell contribution to Parkinson's disease pathogenesis using induced pluripotent stem cells. Cell Mol Life Sci 2021; 78:2081-2094. [PMID: 33210214 PMCID: PMC7966189 DOI: 10.1007/s00018-020-03700-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 10/10/2020] [Accepted: 10/31/2020] [Indexed: 01/02/2023]
Abstract
Parkinson's disease (PD) is an incurable age-linked neurodegenerative disease with characteristic movement impairments that are caused by the progressive loss of dopamine-containing neurons (DAn) within the substantia nigra pars compacta. It has been suggested that misfolded protein aggregates together with neuroinflammation and glial reactivity, may impact nerve cell function, leading to neurodegeneration and diseases, such as PD. However, not many studies have been able to examine the role of human glial cells in the pathogenesis of PD. With the advent of induced pluripotent stem cell (iPSC) technology, it is now possible to reprogram human somatic cells to pluripotency and to generate viable human patient-specific DA neurons and glial cells, providing a tremendous opportunity for dissecting cellular and molecular pathological mechanisms occurring at early stages of PD. This reviews will report on recent work using human iPSC and 3D brain organoid models showing that iPSC technology can be used to recapitulate PD-relevant disease-associated phenotypes, including protein aggregation, cell death or loss of neurite complexity and deficient autophagic vacuoles clearance and focus on the recent co-culture systems that are revealing new insights into the complex interactions that occur between different brain cell types during neurodegeneration. Consequently, such advances are the key to improve our understanding of PD pathology and generate potential targets for new therapies aimed at curing PD patients.
Collapse
Affiliation(s)
- Meritxell Pons-Espinal
- Department of Pathology and Experimental Therapeutics, Bellvitge University Hospital-IDIBELL, 08908, Hospitalet de Llobregat, Spain.
- Institute of Biomedicine (IBUB) of the University of Barcelona (UB), 08028, Barcelona, Spain.
| | - Lucas Blasco-Agell
- Department of Pathology and Experimental Therapeutics, Bellvitge University Hospital-IDIBELL, 08908, Hospitalet de Llobregat, Spain
- Institute of Biomedicine (IBUB) of the University of Barcelona (UB), 08028, Barcelona, Spain
| | - Antonella Consiglio
- Department of Pathology and Experimental Therapeutics, Bellvitge University Hospital-IDIBELL, 08908, Hospitalet de Llobregat, Spain.
- Institute of Biomedicine (IBUB) of the University of Barcelona (UB), 08028, Barcelona, Spain.
- Department of Molecular and Translational Medicine, University of Brescia, Piazza del Mercato, 15, 25121, Brescia, BS, Italy.
| |
Collapse
|
16
|
Niu F, Sharma A, Wang Z, Feng L, Muresanu DF, Sahib S, Tian ZR, Lafuente JV, Buzoianu AD, Castellani RJ, Nozari A, Patnaik R, Wiklund L, Sharma HS. Co-administration of TiO 2-nanowired dl-3-n-butylphthalide (dl-NBP) and mesenchymal stem cells enhanced neuroprotection in Parkinson's disease exacerbated by concussive head injury. PROGRESS IN BRAIN RESEARCH 2020; 258:101-155. [PMID: 33223034 DOI: 10.1016/bs.pbr.2020.09.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
dl-3-n-butylphthalide (dl-NBP) is a powerful antioxidant compound with profound neuroprotective effects in stroke and brain injury. However, its role in Parkinson's disease (PD) is not well known. Traumatic brain injury (TBI) is one of the key factors in precipitating PD like symptoms in civilians and particularly in military personnel. Thus, it would be interesting to explore the possible neuroprotective effects of NBP in PD following concussive head injury (CHI). In this chapter effect of nanowired delivery of NBP together with mesenchymal stem cells (MSCs) in PD with CHI is discussed based on our own investigations. It appears that CHI exacerbates PD pathophysiology in terms of p-tau, α-synuclein (ASNC) levels in the cerebrospinal fluid (CSF) and the loss of TH immunoreactivity in substantia niagra pars compacta (SNpc) and striatum (STr) along with dopamine (DA), dopamine decarboxylase (DOPAC). And homovanillic acid (HVA). Our observations are the first to show that a combination of NBP with MSCs when delivered using nanowired technology induces superior neuroprotective effects in PD brain pathology exacerbated by CHI, not reported earlier.
Collapse
Affiliation(s)
- Feng Niu
- CSPC NBP Pharmaceutical Medicine, Shijiazhuang, Hebei Province, China
| | - Aruna Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden.
| | - Zhenguo Wang
- CSPC NBP Pharmaceutical Medicine, Shijiazhuang, Hebei Province, China
| | - Lianyuan Feng
- Department of Neurology, Bethune International Peace Hospital, Shijiazhuang, Hebei Province, China
| | - Dafin F Muresanu
- Department of Clinical Neurosciences, University of Medicine & Pharmacy, Cluj-Napoca, Romania; "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania
| | - Seaab Sahib
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, AR, United States
| | - Z Ryan Tian
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, AR, United States
| | - José Vicente Lafuente
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), Leioa, Bizkaia, Spain
| | - Anca D Buzoianu
- Department of Clinical Pharmacology and Toxicology, "Iuliu Hatieganu" University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Rudy J Castellani
- Department of Pathology, University of Maryland, Baltimore, MD, United States
| | - Ala Nozari
- Anesthesiology & Intensive Care, Massachusetts General Hospital, Boston, MA, United States
| | - Ranjana Patnaik
- Department of Biomaterials, School of Biomedical Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi, India
| | - Lars Wiklund
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
| | - Hari Shanker Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden.
| |
Collapse
|
17
|
Iovino L, Tremblay ME, Civiero L. Glutamate-induced excitotoxicity in Parkinson's disease: The role of glial cells. J Pharmacol Sci 2020; 144:151-164. [PMID: 32807662 DOI: 10.1016/j.jphs.2020.07.011] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/30/2020] [Accepted: 07/27/2020] [Indexed: 12/11/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system. Glutamate transmission efficiency depends on the correct functionality and expression of a plethora of receptors and transporters, located both on neurons and glial cells. Of note, glutamate reuptake by dedicated transporters prevents its accumulation at the synapse as well as non-physiological spillover. Indeed, extracellular glutamate increase causes aberrant synaptic signaling leading to neuronal excitotoxicity and death. Moreover, extrasynaptic glutamate diffusion is strongly associated with glia reaction and neuroinflammation. Glutamate-induced excitotoxicity is mainly linked to an impaired ability of glial cells to reuptake and respond to glutamate, then this is considered a common hallmark in many neurodegenerative diseases, including Parkinson's disease (PD). In this review, we discuss the function of astrocytes and microglia in glutamate homeostasis, focusing on how glial dysfunction causes glutamate-induced excitotoxicity leading to neurodegeneration in PD.
Collapse
Affiliation(s)
- L Iovino
- Department of Biology, University of Padova, Italy
| | - M E Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, Canada
| | - L Civiero
- Department of Biology, University of Padova, Italy; IRCCS San Camillo Hospital, Venice, Italy.
| |
Collapse
|
18
|
Kam TI, Hinkle JT, Dawson TM, Dawson VL. Microglia and astrocyte dysfunction in parkinson's disease. Neurobiol Dis 2020; 144:105028. [PMID: 32736085 DOI: 10.1016/j.nbd.2020.105028] [Citation(s) in RCA: 160] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 07/01/2020] [Accepted: 07/23/2020] [Indexed: 12/12/2022] Open
Abstract
While glia are essential for regulating the homeostasis in the normal brain, their dysfunction contributes to neurodegeneration in many brain diseases, including Parkinson's disease (PD). Recent studies have identified that PD-associated genes are expressed in glial cells as well as neurons and have crucial roles in microglia and astrocytes. Here, we discuss the role of microglia and astrocytes dysfunction in relation to PD-linked mutations and their implications in PD pathogenesis. A better understanding of microglia and astrocyte functions in PD may provide insights into neurodegeneration and novel therapeutic approaches for PD.
Collapse
Affiliation(s)
- Tae-In Kam
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jared T Hinkle
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ted M Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Valina L Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
19
|
Belloli S, Morari M, Murtaj V, Valtorta S, Moresco RM, Gilardi MC. Translation Imaging in Parkinson's Disease: Focus on Neuroinflammation. Front Aging Neurosci 2020; 12:152. [PMID: 32581765 PMCID: PMC7289967 DOI: 10.3389/fnagi.2020.00152] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 05/06/2020] [Indexed: 12/15/2022] Open
Abstract
Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the appearance of α-synuclein insoluble aggregates known as Lewy bodies. Neurodegeneration is accompanied by neuroinflammation mediated by cytokines and chemokines produced by the activated microglia. Several studies demonstrated that such an inflammatory process is an early event, and contributes to oxidative stress and mitochondrial dysfunctions. α-synuclein fibrillization and aggregation activate microglia and contribute to disease onset and progression. Mutations in different genes exacerbate the inflammatory phenotype in the monogenic compared to sporadic forms of PD. Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) with selected radiopharmaceuticals allow in vivo imaging of molecular modifications in the brain of living subjects. Several publications showed a reduction of dopaminergic terminals and dopamine (DA) content in the basal ganglia, starting from the early stages of the disease. Moreover, non-dopaminergic neuronal pathways are also affected, as shown by in vivo studies with serotonergic and glutamatergic radiotracers. The role played by the immune system during illness progression could be investigated with PET ligands that target the microglia/macrophage Translocator protein (TSPO) receptor. These agents have been used in PD patients and rodent models, although often without attempting correlations with other molecular or functional parameters. For example, neurodegeneration and brain plasticity can be monitored using the metabolic marker 2-Deoxy-2-[18F]fluoroglucose ([18F]-FDG), while oxidative stress can be probed using the copper-labeled diacetyl-bis(N-methyl-thiosemicarbazone) ([Cu]-ATSM) radioligand, whose striatal-specific binding ratio in PD patients seems to correlate with a disease rating scale and motor scores. Also, structural and functional modifications during disease progression may be evaluated by Magnetic Resonance Imaging (MRI), using different parameters as iron content or cerebral volume. In this review article, we propose an overview of in vivo clinical and non-clinical imaging research on neuroinflammation as an emerging marker of early PD. We also discuss how multimodal-imaging approaches could provide more insights into the role of the inflammatory process and related events in PD development.
Collapse
Affiliation(s)
- Sara Belloli
- Institute of Molecular Bioimaging and Physiology (IBFM), CNR, Milan, Italy.,Nuclear Medicine Department, San Raffaele Scientific Institute (IRCCS), Milan, Italy
| | - Michele Morari
- Section of Pharmacology, Department of Medical Sciences, National Institute for Neuroscience, University of Ferrara, Ferrara, Italy
| | - Valentina Murtaj
- Nuclear Medicine Department, San Raffaele Scientific Institute (IRCCS), Milan, Italy.,PhD Program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Silvia Valtorta
- Institute of Molecular Bioimaging and Physiology (IBFM), CNR, Milan, Italy.,Nuclear Medicine Department, San Raffaele Scientific Institute (IRCCS), Milan, Italy.,Medicine and Surgery Department, University of Milano-Bicocca, Milan, Italy
| | - Rosa Maria Moresco
- Institute of Molecular Bioimaging and Physiology (IBFM), CNR, Milan, Italy.,Nuclear Medicine Department, San Raffaele Scientific Institute (IRCCS), Milan, Italy.,Medicine and Surgery Department, University of Milano-Bicocca, Milan, Italy
| | - Maria Carla Gilardi
- Institute of Molecular Bioimaging and Physiology (IBFM), CNR, Milan, Italy.,Medicine and Surgery Department, University of Milano-Bicocca, Milan, Italy
| |
Collapse
|
20
|
Dwyer Z, Rudyk C, Situt D, Beauchamp S, Abdali J, Dinesh A, Legancher N, Sun H, Schlossmacher M, Hayley S. Microglia depletion prior to lipopolysaccharide and paraquat treatment differentially modulates behavioral and neuronal outcomes in wild type and G2019S LRRK2 knock-in mice. Brain Behav Immun Health 2020; 5:100079. [PMID: 34589856 PMCID: PMC8474533 DOI: 10.1016/j.bbih.2020.100079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Substantial data have implicated microglial-driven neuroinflammation in Parkinson's disease (PD) and environmental toxicants have been long expected as triggers of such inflammatory processes. Of course, these environmental insults act in the context of genetic vulnerability factors and in this regard, leucine rich repeat kinase 2 (LRRK2), may play a prominent role. METHODS We used a double hit, lipopolysaccharide (LPS; endotoxin) followed by paraquat (pesticide toxicant) model of PD in mice with the most common LRRK2 mutation G2019S, knockin mice and wild type littermates. In order to assess the contribution of microglia, we depleted these cells (through 14 days of the CSF-1 antagonist, PLX-3397) prior to LPS and paraquat exposure. RESULTS We found that the G2019S mice displayed the greatest signs of behavioral pathology, but that the PLX-3397 induced microglial depletion at the time of LPS exposure diminished toxicity and weight loss and blunted the reduction in home-cage activity with subsequent paraquat exposure. However, neither the PLX-3397 pre-treatment nor the G2019S mutation affected the LPS + paraquat induced loss of substantia nigra pars compacta (SNc) dopamine neurons or elevation of circulating immune (IL-6) or stress (corticosterone) factors. Intriguingly, microglial morphological ratings were basally enhanced in G2019S mice and the PLX-3397 pre-treatment reversed this effect. Moreover, PLX-3397 pre-treatment selectively elevated soluble a-synuclein and SIRT3 levels, while reducing SNc caspase-1 and 3, along with CX3CR1. Hence, the re-populated "new" microglia following cessation of PLX-3397 clearly had an altered phenotype or were immature at the time of sacrifice (i.e. after 11 days). CONCLUSIONS Collectively, these findings suggest that G2019S knock-in and PLX-3397 microglial depletion at the time of LPS exposure affects behavioral, but not neurodegenerative responses to subsequent environmental toxin exposure.
Collapse
Affiliation(s)
- Zach Dwyer
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Chris Rudyk
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Divya Situt
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Sheryl Beauchamp
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Jawaria Abdali
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Anu Dinesh
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | | | - Hongyu Sun
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | | | - Shawn Hayley
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - CLINT (Canadian LRRK2 in inflammation team)
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
- University of Ottawa, Canada
- Ottawa Hospital Research Institute, Canada
| |
Collapse
|
21
|
Cabezudo D, Baekelandt V, Lobbestael E. Multiple-Hit Hypothesis in Parkinson's Disease: LRRK2 and Inflammation. Front Neurosci 2020; 14:376. [PMID: 32410948 PMCID: PMC7199384 DOI: 10.3389/fnins.2020.00376] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/27/2020] [Indexed: 12/17/2022] Open
Abstract
The multiple hit hypothesis for Parkinson’s disease (PD) suggests that an interaction between multiple (genetic and/or environmental) risk factors is needed to trigger the pathology. Leucine-Rich Repeat Kinase 2 (LRRK2) is an interesting protein to study in this context and is the focus of this review. More than 15 years of intensive research have identified several cellular pathways in which LRRK2 is involved, yet its exact physiological role or contribution to PD is not completely understood. Pathogenic mutations in LRRK2 are the most common genetic cause of PD but most likely require additional triggers to develop PD, as suggested by the reduced penetrance of the LRRK2 G2019S mutation. LRRK2 expression is high in immune cells such as monocytes, neutrophils, or dendritic cells, compared to neurons or glial cells and evidence for a role of LRRK2 in the immune system is emerging. This has led to the hypothesis that an inflammatory trigger is needed for pathogenic LRRK2 mutations to induce a PD phenotype. In this review, we will discuss the link between LRRK2 and inflammation and how this could play an active role in PD etiology.
Collapse
Affiliation(s)
- Diego Cabezudo
- Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Veerle Baekelandt
- Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Evy Lobbestael
- Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| |
Collapse
|
22
|
Levy DR, Udgata A, Tourlomousis P, Symmons MF, Hopkins LJ, Bryant CE, Gay NJ. The Parkinson's disease-associated kinase LRRK2 regulates genes required for cell adhesion, polarization, and chemotaxis in activated murine macrophages. J Biol Chem 2020; 295:10857-10867. [PMID: 32111741 PMCID: PMC7397110 DOI: 10.1074/jbc.ra119.011842] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/21/2020] [Indexed: 11/06/2022] Open
Abstract
Leucine-rich repeat kinase 2 (LRRK2) encodes a complex protein that includes kinase and GTPase domains. Genome-wide association studies have identified dominant LRRK2 alleles that predispose their carriers to late-onset idiotypic Parkinson's disease (PD) and also to autoimmune disorders such as Crohn's disease. Considerable evidence indicates that PD initiation and progression involve activation of innate immune functions in microglia, which are brain-resident macrophages. Here we asked whether LRRK2 modifies inflammatory signaling and how this modification might contribute to PD and Crohn's disease. We used RNA-Seq-based high-resolution transcriptomics to compare gene expression in activated primary macrophages derived from WT and Lrrk2 knockout mice. Remarkably, expression of a single gene, Rap guanine nucleotide exchange factor 3 (Rapgef3), was strongly up-regulated in the absence of LRRK2 and down-regulated in its presence. We observed similar regulation of Rapgef3 expression in cells treated with a highly specific inhibitor of LRRK2 protein kinase activity. Rapgef3 encodes an exchange protein, activated by cAMP 1 (EPAC-1), a guanine nucleotide exchange factor that activates the small GTPase Rap-1. Rap-1 mediates cell adhesion, polarization, and directional motility, and our results indicate that LRRK2 modulates chemotaxis of microglia and macrophages. Dominant PD-associated LRRK2 alleles may suppress EPAC-1 activity, further restricting motility and preventing efficient migration of microglia to sites of neuronal damage. Functional analysis in vivo in a subclinical infection model also indicated that Lrrk2 subtly modifies the inflammatory response. These results indicate that LRRK2 modulates the expression of genes involved in murine immune cell chemotaxis.
Collapse
Affiliation(s)
- Daniel R Levy
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, United Kingdom
| | - Atul Udgata
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, United Kingdom
| | - Panagiotis Tourlomousis
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - Martyn F Symmons
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, United Kingdom
| | - Lee J Hopkins
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - Clare E Bryant
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - Nicholas J Gay
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, United Kingdom
| |
Collapse
|
23
|
Kelly R, Joers V, Tansey MG, McKernan DP, Dowd E. Microglial Phenotypes and Their Relationship to the Cannabinoid System: Therapeutic Implications for Parkinson's Disease. Molecules 2020; 25:molecules25030453. [PMID: 31973235 PMCID: PMC7037317 DOI: 10.3390/molecules25030453] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/11/2022] Open
Abstract
Parkinson’s disease is a neurodegenerative disorder, the motor symptoms of which are associated classically with Lewy body formation and nigrostriatal degeneration. Neuroinflammation has been implicated in the progression of this disease, by which microglia become chronically activated in response to α-synuclein pathology and dying neurons, thereby acquiring dishomeostatic phenotypes that are cytotoxic and can cause further neuronal death. Microglia have a functional endocannabinoid signaling system, expressing the cannabinoid receptors in addition to being capable of synthesizing and degrading endocannabinoids. Alterations in the cannabinoid system—particularly an upregulation in the immunomodulatory CB2 receptor—have been demonstrated to be related to the microglial activation state and hence the microglial phenotype. This paper will review studies that examine the relationship between the cannabinoid system and microglial activation, and how this association could be manipulated for therapeutic benefit in Parkinson’s disease.
Collapse
Affiliation(s)
- Rachel Kelly
- Pharmacology & Therapeutics, National University of Ireland, H91 W5P7 Galway, Ireland; (R.K.); (D.P.M.)
| | - Valerie Joers
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32611, USA; (V.J.); (M.G.T.)
| | - Malú G. Tansey
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32611, USA; (V.J.); (M.G.T.)
- Center for Translation Research in Neurodegenerative Disease, University of Florida College of Medicine, Gainesville, FL 32611, USA
| | - Declan P. McKernan
- Pharmacology & Therapeutics, National University of Ireland, H91 W5P7 Galway, Ireland; (R.K.); (D.P.M.)
| | - Eilís Dowd
- Pharmacology & Therapeutics, National University of Ireland, H91 W5P7 Galway, Ireland; (R.K.); (D.P.M.)
- Correspondence:
| |
Collapse
|
24
|
Chamera K, Trojan E, Szuster-Głuszczak M, Basta-Kaim A. The Potential Role of Dysfunctions in Neuron-Microglia Communication in the Pathogenesis of Brain Disorders. Curr Neuropharmacol 2020; 18:408-430. [PMID: 31729301 PMCID: PMC7457436 DOI: 10.2174/1570159x17666191113101629] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/15/2019] [Accepted: 11/10/2019] [Indexed: 12/18/2022] Open
Abstract
The bidirectional communication between neurons and microglia is fundamental for the proper functioning of the central nervous system (CNS). Chemokines and clusters of differentiation (CD) along with their receptors represent ligand-receptor signalling that is uniquely important for neuron - microglia communication. Among these molecules, CX3CL1 (fractalkine) and CD200 (OX-2 membrane glycoprotein) come to the fore because of their cell-type-specific localization. They are principally expressed by neurons when their receptors, CX3CR1 and CD200R, respectively, are predominantly present on the microglia, resulting in the specific axis which maintains the CNS homeostasis. Disruptions to this balance are suggested as contributors or even the basis for many neurological diseases. In this review, we discuss the roles of CX3CL1, CD200 and their receptors in both physiological and pathological processes within the CNS. We want to underline the critical involvement of these molecules in controlling neuron - microglia communication, noting that dysfunctions in their interactions constitute a key factor in severe neurological diseases, such as schizophrenia, depression and neurodegeneration-based conditions.
Collapse
Affiliation(s)
- Katarzyna Chamera
- Department of Experimental Neuroendocrinology, Laboratory of Immunoendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St. 31-343Kraków, Poland
| | - Ewa Trojan
- Department of Experimental Neuroendocrinology, Laboratory of Immunoendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St. 31-343Kraków, Poland
| | - Magdalena Szuster-Głuszczak
- Department of Experimental Neuroendocrinology, Laboratory of Immunoendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St. 31-343Kraków, Poland
| | - Agnieszka Basta-Kaim
- Department of Experimental Neuroendocrinology, Laboratory of Immunoendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St. 31-343Kraków, Poland
| |
Collapse
|
25
|
Russo I, Kaganovich A, Ding J, Landeck N, Mamais A, Varanita T, Biosa A, Tessari I, Bubacco L, Greggio E, Cookson MR. Transcriptome analysis of LRRK2 knock-out microglia cells reveals alterations of inflammatory- and oxidative stress-related pathways upon treatment with α-synuclein fibrils. Neurobiol Dis 2019; 129:67-78. [PMID: 31102768 PMCID: PMC6749993 DOI: 10.1016/j.nbd.2019.05.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/05/2019] [Accepted: 05/14/2019] [Indexed: 11/19/2022] Open
Abstract
Several previous studies have linked the Parkinson's disease (PD) gene LRRK2 to the biology of microglia cells. However, the precise ways in which LRRK2 affects microglial function have not been fully resolved. Here, we used the RNA-Sequencing to obtain transcriptomic profiles of LRRK2 wild-type (WT) and knock-out (KO) microglia cells treated with α-synuclein pre-formed fibrils (PFFs) or lipopolysaccharide (LPS) as a general inflammatory insult. We observed that, although α-synuclein PFFs and LPS mediate overlapping gene expression profiles in microglia, there are also distinct responses to each stimulus. α-Synuclein PFFs trigger alterations of oxidative stress-related pathways with the mitochondrial dismutase Sod2 as a strongly differentially regulated gene. We validated SOD2 at mRNA and protein levels. Furthermore, we found that LRRK2 KO microglia cells reported attenuated induction of mitochondrial SOD2 in response to α-synuclein PFFs, indicating a potential contribution of LRRK2 to oxidative stress-related pathways. We validate several genes in vivo using single-cell RNA-Seq from acutely isolated microglia after striatal injection of LPS into the mouse brain. Overall, these results suggest that microglial LRRK2 may contribute to the pathogenesis of PD via altered oxidative stress signaling.
Collapse
Affiliation(s)
- Isabella Russo
- Department of Biology, University of Padova, Padova 35131, Italy; Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy.
| | - Alice Kaganovich
- Department of Biology, University of Padova, Padova 35131, Italy; Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jinhui Ding
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Natalie Landeck
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Adamantios Mamais
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Tatiana Varanita
- Department of Biology, University of Padova, Padova 35131, Italy.
| | - Alice Biosa
- Department of Biology, University of Padova, Padova 35131, Italy.
| | - Isabella Tessari
- Department of Biology, University of Padova, Padova 35131, Italy.
| | - Luigi Bubacco
- Department of Biology, University of Padova, Padova 35131, Italy.
| | - Elisa Greggio
- Department of Biology, University of Padova, Padova 35131, Italy.
| | - Mark R Cookson
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
26
|
Rudyk C, Dwyer Z, Hayley S. Leucine-rich repeat kinase-2 (LRRK2) modulates paraquat-induced inflammatory sickness and stress phenotype. J Neuroinflammation 2019; 16:120. [PMID: 31174552 PMCID: PMC6554960 DOI: 10.1186/s12974-019-1483-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 04/18/2019] [Indexed: 01/11/2023] Open
Abstract
Background Leucine-rich repeat kinase 2 (LRRK2) is a common gene implicated in Parkinson’s disease (PD) and is also thought to be fundamentally involved in numerous immune functions. Thus, we assessed the role of LRRK2 in the context of the effects of the environmental toxicant, paraquat, that has been implicated in PD and is known to affect inflammatory processes. Methods Male LRRK2 knockout (KO) and transgenic mice bearing the G2019S LRRK2 mutation (aged 6–8 months) or their littermate controls were exposed to paraquat (two times per week for 3 weeks), and sickness measures, motivational scores, and total home-cage activity levels were assessed. Following sacrifice, western blot and ELISA assays were performed to see whether or not LRRK2 expression would alter processes related to plasticity, immune response processes, or the stress response. Results Paraquat-induced signs of sickness, inflammation (elevated IL-6), and peripheral toxicity (e.g., organ weight) were completely prevented by LRRK2 knockout. In fact, LRRK2 knockout dramatically reduced not only signs of illness, but also the motivational (nest building) and home-cage activity deficits induced by paraquat. Although LRRK2 deficiency did not affect the striatal BDNF reduction that was provoked by paraquat, it did blunt the corticosterone elevation induced by paraquat, raising the possibility that LRRK2 may modulate aspects of the HPA stress axis. Accordingly, we found that transgenic mice bearing the G2019S LRRK2 mutation had elevated basal corticosterone, along with diminished hippocampal 5-HT1A levels. Conclusion We are the first to show the importance of LRRK2 in the peripheral neurotoxic and stressor-like effects of paraquat. These data are consistent with LRRK2 playing a role in the general inflammatory tone and stressor effects induced by environmental toxicant exposure.
Collapse
Affiliation(s)
- Chris Rudyk
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Zach Dwyer
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Shawn Hayley
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
| | | |
Collapse
|
27
|
Lipopolysaccharide-Induced Neuroinflammation as a Bridge to Understand Neurodegeneration. Int J Mol Sci 2019; 20:ijms20092293. [PMID: 31075861 PMCID: PMC6539529 DOI: 10.3390/ijms20092293] [Citation(s) in RCA: 253] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/03/2019] [Accepted: 05/05/2019] [Indexed: 12/19/2022] Open
Abstract
A large body of experimental evidence suggests that neuroinflammation is a key pathological event triggering and perpetuating the neurodegenerative process associated with many neurological diseases. Therefore, different stimuli, such as lipopolysaccharide (LPS), are used to model neuroinflammation associated with neurodegeneration. By acting at its receptors, LPS activates various intracellular molecules, which alter the expression of a plethora of inflammatory mediators. These factors, in turn, initiate or contribute to the development of neurodegenerative processes. Therefore, LPS is an important tool for the study of neuroinflammation associated with neurodegenerative diseases. However, the serotype, route of administration, and number of injections of this toxin induce varied pathological responses. Thus, here, we review the use of LPS in various models of neurodegeneration as well as discuss the neuroinflammatory mechanisms induced by this toxin that could underpin the pathological events linked to the neurodegenerative process.
Collapse
|
28
|
Tremblay ME, Cookson MR, Civiero L. Glial phagocytic clearance in Parkinson's disease. Mol Neurodegener 2019; 14:16. [PMID: 30953527 PMCID: PMC6451240 DOI: 10.1186/s13024-019-0314-8] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 03/15/2019] [Indexed: 12/21/2022] Open
Abstract
An emerging picture suggests that glial cells' loss of beneficial roles or gain of toxic functions can contribute to neurodegenerative conditions. Among glial cells, microglia and astrocytes have been shown to play phagocytic roles by engulfing synapses, apoptotic cells, cell debris, and released toxic proteins. As pathogenic protein accumulation is a key feature in Parkinson's disease (PD), compromised phagocytic clearance might participate in PD pathogenesis. In contrast, enhanced, uncontrolled and potentially toxic glial clearance capacity could contribute to synaptic degeneration. Here, we summarize the current knowledge of the molecular mechanisms underlying microglial and astrocytic phagocytosis, focusing on the possible implication of phagocytic dysfunction in neuronal degeneration. Several endo-lysosomal proteins displaying genetic variants in PD are highly expressed by microglia and astrocytes. We also present the evidence that lysosomal defects can affect phagocytic clearance and discuss the therapeutic relevance of restoring or enhancing lysosomal function in PD.
Collapse
Affiliation(s)
- Marie-Eve Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Quebec, QC Canada
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Quebec, QC Canada
| | - Mark R. Cookson
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD USA
| | - Laura Civiero
- Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
| |
Collapse
|
29
|
Weykopf B, Haupt S, Jungverdorben J, Flitsch LJ, Hebisch M, Liu G, Suzuki K, Belmonte JCI, Peitz M, Blaess S, Till A, Brüstle O. Induced pluripotent stem cell-based modeling of mutant LRRK2-associated Parkinson's disease. Eur J Neurosci 2019; 49:561-589. [PMID: 30656775 PMCID: PMC7114274 DOI: 10.1111/ejn.14345] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 12/13/2018] [Accepted: 01/10/2019] [Indexed: 12/13/2022]
Abstract
Recent advances in cell reprogramming have enabled assessment of disease-related cellular traits in patient-derived somatic cells, thus providing a versatile platform for disease modeling and drug development. Given the limited access to vital human brain cells, this technology is especially relevant for neurodegenerative disorders such as Parkinson's disease (PD) as a tool to decipher underlying pathomechanisms. Importantly, recent progress in genome-editing technologies has provided an ability to analyze isogenic induced pluripotent stem cell (iPSC) pairs that differ only in a single genetic change, thus allowing a thorough assessment of the molecular and cellular phenotypes that result from monogenetic risk factors. In this review, we summarize the current state of iPSC-based modeling of PD with a focus on leucine-rich repeat kinase 2 (LRRK2), one of the most prominent monogenetic risk factors for PD linked to both familial and idiopathic forms. The LRRK2 protein is a primarily cytosolic multi-domain protein contributing to regulation of several pathways including autophagy, mitochondrial function, vesicle transport, nuclear architecture and cell morphology. We summarize iPSC-based studies that contributed to improving our understanding of the function of LRRK2 and its variants in the context of PD etiopathology. These data, along with results obtained in our own studies, underscore the multifaceted role of LRRK2 in regulating cellular homeostasis on several levels, including proteostasis, mitochondrial dynamics and regulation of the cytoskeleton. Finally, we expound advantages and limitations of reprogramming technologies for disease modeling and drug development and provide an outlook on future challenges and expectations offered by this exciting technology.
Collapse
Affiliation(s)
- Beatrice Weykopf
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
- Life & Brain GmbHCellomics UnitBonnGermany
- Precision Neurology Program & Advanced Center for Parkinson's Disease ResearchHarvard Medical School and Brigham & Women's HospitalBostonMassachusetts
| | | | - Johannes Jungverdorben
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
- Memorial Sloan Kettering Cancer CenterNew York CityNew York
| | - Lea Jessica Flitsch
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
| | - Matthias Hebisch
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
| | - Guang‐Hui Liu
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijingChina
| | - Keiichiro Suzuki
- Gene Expression LaboratoryThe Salk Institute for Biological StudiesLa JollaCalifornia
| | | | - Michael Peitz
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
- German Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | - Sandra Blaess
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
| | - Andreas Till
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
- Life & Brain GmbHCellomics UnitBonnGermany
| | - Oliver Brüstle
- Institute of Reconstructive NeurobiologyUniversity of Bonn School of Medicine & University Hospital BonnBonnGermany
| |
Collapse
|
30
|
Cresto N, Gardier C, Gubinelli F, Gaillard MC, Liot G, West AB, Brouillet E. The unlikely partnership between LRRK2 and α-synuclein in Parkinson's disease. Eur J Neurosci 2018; 49:339-363. [PMID: 30269383 DOI: 10.1111/ejn.14182] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 09/11/2018] [Accepted: 09/17/2018] [Indexed: 12/19/2022]
Abstract
Our understanding of the mechanisms underlying Parkinson's disease, the once archetypical nongenetic neurogenerative disorder, has dramatically increased with the identification of α-synuclein and LRRK2 pathogenic mutations. While α-synuclein protein composes the aggregates that can spread through much of the brain in disease, LRRK2 encodes a multidomain dual-enzyme distinct from any other protein linked to neurodegeneration. In this review, we discuss emergent datasets from multiple model systems that suggest these unlikely partners do interact in important ways in disease, both within cells that express both LRRK2 and α-synuclein as well as through more indirect pathways that might involve neuroinflammation. Although the link between LRRK2 and disease can be understood in part through LRRK2 kinase activity (phosphotransferase activity), α-synuclein toxicity is multilayered and plausibly interacts with LRRK2 kinase activity in several ways. We discuss common protein interactors like 14-3-3s that may regulate α-synuclein and LRRK2 in disease. Finally, we examine cellular pathways and outcomes common to both mutant α-synuclein expression and LRRK2 activity and points of intersection. Understanding the interplay between these two unlikely partners in disease may provide new therapeutic avenues for PD.
Collapse
Affiliation(s)
- Noémie Cresto
- Neurodegenerative Diseases Laboratory, UMR9199, CEA, CNRS, Université Paris Sud, Université Paris-Saclay, and MIRCen (Molecular Imaging Research Centre), Institut François Jacob, DRF, CEA, Fontenay-aux-Roses, France
| | - Camille Gardier
- Neurodegenerative Diseases Laboratory, UMR9199, CEA, CNRS, Université Paris Sud, Université Paris-Saclay, and MIRCen (Molecular Imaging Research Centre), Institut François Jacob, DRF, CEA, Fontenay-aux-Roses, France
| | - Francesco Gubinelli
- Neurodegenerative Diseases Laboratory, UMR9199, CEA, CNRS, Université Paris Sud, Université Paris-Saclay, and MIRCen (Molecular Imaging Research Centre), Institut François Jacob, DRF, CEA, Fontenay-aux-Roses, France
| | - Marie-Claude Gaillard
- Neurodegenerative Diseases Laboratory, UMR9199, CEA, CNRS, Université Paris Sud, Université Paris-Saclay, and MIRCen (Molecular Imaging Research Centre), Institut François Jacob, DRF, CEA, Fontenay-aux-Roses, France
| | - Géraldine Liot
- Neurodegenerative Diseases Laboratory, UMR9199, CEA, CNRS, Université Paris Sud, Université Paris-Saclay, and MIRCen (Molecular Imaging Research Centre), Institut François Jacob, DRF, CEA, Fontenay-aux-Roses, France
| | - Andrew B West
- Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Emmanuel Brouillet
- Neurodegenerative Diseases Laboratory, UMR9199, CEA, CNRS, Université Paris Sud, Université Paris-Saclay, and MIRCen (Molecular Imaging Research Centre), Institut François Jacob, DRF, CEA, Fontenay-aux-Roses, France
| |
Collapse
|
31
|
Joe EH, Choi DJ, An J, Eun JH, Jou I, Park S. Astrocytes, Microglia, and Parkinson's Disease. Exp Neurobiol 2018; 27:77-87. [PMID: 29731673 PMCID: PMC5934545 DOI: 10.5607/en.2018.27.2.77] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 04/14/2018] [Accepted: 04/16/2018] [Indexed: 12/12/2022] Open
Abstract
Astrocytes and microglia support well-being and well-function of the brain through diverse functions in both intact and injured brain. For example, astrocytes maintain homeostasis of microenvironment of the brain through up-taking ions and neurotransmitters, and provide growth factors and metabolites for neurons, etc. Microglia keep surveying surroundings, and remove abnormal synapses or respond to injury by isolating injury sites and expressing inflammatory cytokines. Therefore, their loss and/or functional alteration may be directly linked to brain diseases. Since Parkinson's disease (PD)-related genes are expressed in astrocytes and microglia, mutations of these genes may alter the functions of these cells, thereby contributing to disease onset and progression. Here, we review the roles of astrocytes and microglia in intact and injured brain, and discuss how PD genes regulate their functions.
Collapse
Affiliation(s)
- Eun-Hye Joe
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
| | - Dong-Joo Choi
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
| | - Jiawei An
- Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea
| | - Jin-Hwa Eun
- Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea
| | - Ilo Jou
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
| | - Sangmyun Park
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
| |
Collapse
|
32
|
Abstract
Mutations in the gene encoding leucine-rich repeat kinase 2 (LRRK2) are known today as the most common genetic cause of Parkinson's disease (PD). LRRK2 is a large protein that is hypothesized to regulate other proteins as a scaffold in downstream signaling pathways. This is supported by the multiple domain composition of LRRK2 with several protein-protein interaction domains combined with kinase and GTPase activity. LRRK2 is highly phosphorylated at sites that are strictly controlled by upstream regulators, including its own kinase domain. In cultured cells, most pathogenic mutants display increased autophosphorylation at S1292, but decreased phosphorylation at sites controlled by other kinases. We only begin to understand how LRRK2 phosphorylation is regulated and how this impacts its physiological and pathological function. Intriguingly, LRRK2 kinase inhibition, currently one of the most prevailing disease-modifying therapeutic strategies for PD, induces LRRK2 dephosphorylation at sites that are also dephosphorylated in pathogenic variants. In addition, LRRK2 kinase inhibition can induce LRRK2 protein degradation, which might be related to the observed inhibitor-induced adverse effects on the lung in rodents and non-human primates, as it resembles the lung pathology in LRRK2 knock-out animals. In this review, we will provide an overview of how LRRK2 phosphorylation is regulated and how this complex regulation relates to several molecular and cellular features of LRRK2.
Collapse
Affiliation(s)
- Tina De Wit
- 1 Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Veerle Baekelandt
- 1 Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Evy Lobbestael
- 1 Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| |
Collapse
|
33
|
The impact of murine LRRK2 G2019S transgene overexpression on acute responses to inflammatory challenge. Brain Behav Immun 2018; 67:246-256. [PMID: 28893563 DOI: 10.1016/j.bbi.2017.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/07/2017] [Accepted: 09/02/2017] [Indexed: 02/07/2023] Open
Abstract
The most common Parkinson's disease (PD) mutation is the gain-of-function LRRK2 G2019S variant, which has also been linked to inflammatory disease states. Yet, little is known of the role of G2019S in PD related complex behavioral or immune/hormonal processes in response to inflammatory/toxicant challenges. Hence, we characterized the behavioral, neuroendocrine-immune and central monoaminergic responses in G2019S overexpressing mutants following systemic interferon-gamma (IFN-γ) or lipopolysaccharide (LPS) administration. Although LPS markedly (and IFN-γ modestly in some cases) increased cytokine and corticosterone levels, while inducing pronounced sickness and home-cage activity deficits, the G2019S mutation had no effect on these parameters. No differences were observed with regards to brain microglia with the acute LPS injection, regardless of genotype. Nor did the G2019S mutation influence neurotransmitter levels within the medial prefrontal cortex or paraventricular nucleus of the hypothalamus. However, the LRRK2 G2019S transgenic mice did have altered monoamine levels within the striatum and hippocampus. Indeed, G2019S mice had altered basal levels and turnover of dopamine within the striatum, along with changes in hippocampal serotonin and norepinephrine activity in response to LPS and IFN-γ. The present findings suggest the importance of murine G2019S in hippocampal and striatal neurotransmission, but that the transgene didn't appear to be involved in functional behavioral and stress-like hormonal and cytokine changes provoked by inflammatory insults.
Collapse
|
34
|
Park J, Lee JW, Cooper SC, Broxmeyer HE, Cannon JR, Kim CH. Parkinson disease-associated LRRK2 G2019S transgene disrupts marrow myelopoiesis and peripheral Th17 response. J Leukoc Biol 2017; 102:1093-1102. [PMID: 28751472 DOI: 10.1189/jlb.1a0417-147rr] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disease, whereas Crohn's disease is an inflammatory bowel disease. Interestingly, polymorphisms in the LRRK2 gene have been identified as risk factors for both diseases. LRRK2 G2019S is the most prevalent mutation found in PD. To gain insights into the role of the LRRK2 G2019S gene on the development and activation of the immune system in the brain-gut axis, we investigated the effect of LRRK2 G2019S on bone marrow myeloid progenitors and myeloid cell function in the periphery. We used bacterial artificial chromosome transgenic rats harboring the human LRRK2 G2019S gene. LRRK2 G2019S transgene decreased the numbers of monocytic and granulocytic progenitors in the bone marrow. However, the numbers of peripheral, immature myeloid cells with suppressive activity were increased in the gut and blood circulation of LRRK2 G2019S compared with control rats in various acute and chronic inflammatory responses. In inflammatory conditions, Th17 cell activity was suppressed, but tissue-associated phylum Bacteroidetes was abnormally increased in the intestine of LRRK2 G2019S rats. The abnormally expanded myeloid cells because of the LRRK2 G2019S gene were highly suppressive on Th17 cell differentiation. Moreover, we found that inhibition of LRRK2 kinase affects myeloid progenitors and myeloid cell differentiation. Taken together, the results indicate that abnormal LRRK2 activity can alter bone marrow myelopoiesis, peripheral myeloid cell differentiation, and intestinal immune homeostasis. These findings may have ramifications in immune and inflammatory responses in patients with LRRK2 abnormalities.
Collapse
Affiliation(s)
- Jeongho Park
- Laboratory of Immunology and Hematopoiesis, Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana, USA
| | - Jang-Won Lee
- School of Health Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Scott C Cooper
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Hal E Broxmeyer
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, Indiana, USA.,Purdue Institute of Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Chang H Kim
- Laboratory of Immunology and Hematopoiesis, Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana, USA; .,Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA.,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA.,Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA; and.,Purdue Institute of Inflammation, Immunology and Infectious Diseases, Purdue University, West Lafayette, Indiana, USA
| |
Collapse
|
35
|
LRRK2 in peripheral and central nervous system innate immunity: its link to Parkinson's disease. Biochem Soc Trans 2017; 45:131-139. [PMID: 28202666 PMCID: PMC5652224 DOI: 10.1042/bst20160262] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/09/2016] [Accepted: 10/12/2016] [Indexed: 12/14/2022]
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are found in familial and idiopathic cases of Parkinson's disease (PD), but are also associated with immune-related disorders, notably Crohn's disease and leprosy. Although the physiological function of LRRK2 protein remains largely elusive, increasing evidence suggests that it plays a role in innate immunity, a process that also has been implicated in neurodegenerative diseases, including PD. Innate immunity involves macrophages and microglia, in which endogenous LRRK2 expression is precisely regulated and expression is strongly up-regulated upon cell activation. This brief report discusses the current understanding of the involvement of LRRK2 in innate immunity particularly in relation to PD, critically examining its role in myeloid cells, particularly macrophages and microglia.
Collapse
|
36
|
Wilkins HM, Weidling IW, Ji Y, Swerdlow RH. Mitochondria-Derived Damage-Associated Molecular Patterns in Neurodegeneration. Front Immunol 2017; 8:508. [PMID: 28491064 PMCID: PMC5405073 DOI: 10.3389/fimmu.2017.00508] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 04/12/2017] [Indexed: 12/21/2022] Open
Abstract
Inflammation is increasingly implicated in neurodegenerative disease pathology. As no acquired pathogen appears to drive this inflammation, the question of what does remains. Recent advances indicate damage-associated molecular pattern (DAMP) molecules, which are released by injured and dying cells, can cause specific inflammatory cascades. Inflammation, therefore, can be endogenously induced. Mitochondrial components induce inflammatory responses in several pathological conditions. Due to evidence such as this, a number of mitochondrial components, including mitochondrial DNA, have been labeled as DAMP molecules. In this review, we consider the contributions of mitochondrial-derived DAMPs to inflammation observed in neurodegenerative diseases.
Collapse
Affiliation(s)
- Heather M Wilkins
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA.,University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA
| | - Ian W Weidling
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Yan Ji
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA.,University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA
| | - Russell H Swerdlow
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA.,University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.,Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
| |
Collapse
|
37
|
Abstract
Parkinson disease is the second-most common neurodegenerative disorder that affects 2-3% of the population ≥65 years of age. Neuronal loss in the substantia nigra, which causes striatal dopamine deficiency, and intracellular inclusions containing aggregates of α-synuclein are the neuropathological hallmarks of Parkinson disease. Multiple other cell types throughout the central and peripheral autonomic nervous system are also involved, probably from early disease onwards. Although clinical diagnosis relies on the presence of bradykinesia and other cardinal motor features, Parkinson disease is associated with many non-motor symptoms that add to overall disability. The underlying molecular pathogenesis involves multiple pathways and mechanisms: α-synuclein proteostasis, mitochondrial function, oxidative stress, calcium homeostasis, axonal transport and neuroinflammation. Recent research into diagnostic biomarkers has taken advantage of neuroimaging in which several modalities, including PET, single-photon emission CT (SPECT) and novel MRI techniques, have been shown to aid early and differential diagnosis. Treatment of Parkinson disease is anchored on pharmacological substitution of striatal dopamine, in addition to non-dopaminergic approaches to address both motor and non-motor symptoms and deep brain stimulation for those developing intractable L-DOPA-related motor complications. Experimental therapies have tried to restore striatal dopamine by gene-based and cell-based approaches, and most recently, aggregation and cellular transport of α-synuclein have become therapeutic targets. One of the greatest current challenges is to identify markers for prodromal disease stages, which would allow novel disease-modifying therapies to be started earlier.
Collapse
|